Files
Abstract
Cardiovascular disease (CVD), the leading cause of death in the United States, isprecipitated by lifestyle risk factors including dyslipidemia, poor glycemic control, and
obesity. Elevated oxidative stress is a hallmark of CVD risk factors, in which high
oxidative stress accelerates disease progression. Vascular function is highly sensitive to
changes in oxidative stress. The quantification of peripheral vascular function using flowmediated dilation (FMD) has been correlated with coronary artery function and CVD risk. Previous research has shown beneficial changes to CVD risk factors following a pecan-enriched diet in healthy and at-risk populations. However, the effect of daily pecan consumption on vascular function and cognition has not yet been evaluated, nor has a 4-week pecan intervention been conducted in healthy older adults. The objective was to assess the effect of a pecan-enriched diet on both vascular function and other predictors of CVD risk including, blood lipids, oxidative stress, antioxidant status, markers of glycemia, cognitive performance, and appetite. In this randomized, controlled trial, healthy older adults were randomized to either a pecan-diet (68g/day) or a nut-free control for 4-weeks. In manuscript #1 (chapter #3), postprandial microvascular reactivity and triglycerides improved for pecan vs. control, with no changes in macrovascular function. Furthermore, in manuscript #1 (chapter #3), cholesterol profiles improved for pecan vs. control. In manuscript #2 (chapter #4), there was a significant reduction of fasting glucose and postprandial lipid peroxidation within the pecan group. For manuscript #3, there was enhanced fasting and postprandial PYY incretion and reduced appetite intensity for pecan vs. control (chapter #5) which may have contributed a significant difference in theoretical vs. actual body weight and body fat percent changes for the pecan (chapter #5). Lastly, there were no differences in cognitive performance between pecan and control (manuscript #4; chapter #6); all participants improved in performance on executive function, memory, processing speed, and attention tasks following the intervention. Altogether, a 4-week pecan-enriched diet led to improved cardiovascular health, microvascular function, and suppressed appetite in healthy older adults. Thus, the inclusion of pecans in the diet may be important for diminishing lifestyle-related increases in CVD risk in healthy aging.